[hillfooter]

Just bring the feeders in overnight to prevent vermin.

Or the usual method is to hang the feed dispenser at chx back height under cover (to protect from being fouled and the weather and vermin.
HF

That's what I do but I have read that mice are adept at negotiating this obstacle.

Yes mice are amazingly acrobatic and seemingly can get a grip on the smoothest of near vertical surfaces.  I have seen mice climbing down a cord used to hang feed and what I usually do is us a solid wire and or put a 15cm+ diameter disk (like a CD) part way down the cord so they can't get down the cord and fall off.  Close by raised areas like a brick which they can jump from should also be avoided as they can jump quite well too.

I have a large deep polythene trug which I discovered was an excellent mouse trap.  I use it for mixing food, particularly medicating pellets with flubenvet wormer.  I always add a slurp of corn oil to help the powder stick to the pellets which leaves the sides of the trug slightly greasy.  Mice can get in by climbing the woodpile next to where I left it but they can't climb or jump out.  The first time I left it out the next morning I had caught 9 mice .  After a few days I soon had eliminated any mouse problem in my feed shed .  By the way these are very useful items for mixing feed, carrying pellets for topping up feeders etc.  More versitile than buckets.
HF

HF

[ANHBUC]

Thanks for the information hillfooter.  I haven't seen a mouse in our garden since the girls got a taste for them!  Sure they are there but in a lot smaller numbers now.   

[Dominic]

I have stone grit and oyster shell available at all times.
When they free range, the stone usage plummets, they find it in the garden, when they are confined, the oyster grit usage plummets, because theres plenty in the food.

I just find it easier to have all three available at all times and leave them to it.

[diamond_lil]

You don't half learn a lot form this forum - trouble is I spend so much time reading it I never get anything done!

Anyway, to go back to your original question about grit, this is my experience but you lot may well disagree!

We had a problem a few years ago with hens producing eggs with very thin shells. They would collapse as soon as you picked them up. So, despite ours free ranging during the day, and helping themselves to large amounts of gravel off the drive, I give them access to a mixture of grit and oyster shell. The grit provides the crop with its grinding ability and the oyster shell boosts the calcium. They get layers pellets when they are shut in - over night until about 11 a.m. The thin shell problem went away. (I can't leave the layers pellets out for them or the wild guinea fowl and our ducks would eat the lot - and the husband would complain about the cost!)

Thanks for all you helpful comments over the years. Happy Crimble.